Banca de DEFESA: FABIANO EDUARDO MARQUES CEZARIO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : FABIANO EDUARDO MARQUES CEZARIO
DATE: 28/11/2023
TIME: 14:00
LOCAL: UFABC - Campus do Santo André
TITLE:

STUDY OF THE EFFECTS OF QUENCHING AND PARTITIONING HEAT TREATMENTS ON THE MICROSTRUCTURE AND MECHANICAL BEHAVIOR OF SAE 9254 STEEL

PAGES: 115
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Metalurgia de Transformação
SPECIALTY: Tratamentos Térmicos, Mecânicos e Químicos
SUMMARY:

Technological advancements suggest the development and processing of new materials and technologies that can provide economically competitive materials with the desired mechanical properties. In order to enhance the mechanical properties of a commercially available medium-carbon silicon steel, new quenching and partitioning (Q&P) processes were designed to create a complex microstructure by controlling the carbon partitioning kinetics. Dilatation curves were carefully analyzed to determine the phase transformations that occurred during the applied heat treatment. X-ray diffraction (XRD) was used to identify the phases present in the material, quantify retained austenite, and estimate the density of dislocations, microstrain, and crystallite size in the steel matrix. Electron backscatter diffraction (EBSD) was employed to map the crystallographic orientations and microstructures of individual grains, thus correlating them with the mechanical properties of the samples. For a more detailed and thorough microstructural analysis, scanning electron microscopy (SEM) was conducted, allowing for the observation of microstructures and morphologies resulting from the proposed heat treatments. Nanoindentation was used to confirm the presence of retained austenite in the samples. Vickers microhardness testing and tensile testing revealed an improvement in the final tensile strength of all treated samples compared to the initial microstructure. Pin-on-disk testing indicated that the mass loss of the as-received sample was approximately 0.118 g, whereas the QPI-575-125-325 sample exhibited a mass loss of 0.036 g, and the QP-550-125-375 sample showed only a 0.003 g mass loss, which is approximately 40 times smaller than that of the as-received sample. All these techniques confirmed the effectiveness of the proposed heat treatments in this research.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 3068039 - MOHAMMAD MASOUMI
Membro Titular - Examinador(a) Interno ao Programa - 1671298 - RENATO ALTOBELLI ANTUNES
Membro Titular - Examinador(a) Externo à Instituição - DANY MICHELL ANDRADE CENTENO
Membro Suplente - Examinador(a) Interno ao Programa - 1646041 - CARLOS TRIVENO RIOS
Membro Suplente - Examinador(a) Interno ao Programa - 1925199 - ANIBAL DE ANDRADE MENDES FILHO
Membro Suplente - Examinador(a) Externo à Instituição - SILVANO LEAL DOS SANTOS